Evaporative coolers represent an effective and econonomical means for cooling homes in areas of low humidity, and they are becoming even more practical with the increasing costs of electric power. In the past, however, evaporative coolers had several objectionable characteristics. An objective of the present invention is to overcome these objectionable characteristics.
A major problem with evaporative coolers in the past has been that it was considered impractical to contrbl them with a thermostat, and the coolers were usually turned on and off by means of a manually operated switch. Accordingly, it was necessary for the user constantly to turn the cooler on or off, usually in an unsuccessful attempt to maintain a desirable temperature.
The system of the present invention makes it possible to control an evaporative cooler with a precision thermostat. In addition, the same thermostat is used to control a gas heater, or the like. Thus, the thermostat is set to a desired temperature, and the system of the invention takes over and automatically and accurately maintains the set temperature for summer or winter.
The system of the invention includes the following advantages: the evaporative cooler is turned on only when it is needed; the blower of the cooler is automatically switched between low and high speeds, as needed in order to maintain a constant temperature; the system is easily adapted to an existing cooler and heating system, as well as to new installations; and the system provides automatic change-over from cooling to heating.
In addition, the system of the invention renders it impossible for the cooler and heater to be on at the same time, thereby eliminating a source of wasted energy. The system also saves energy because the evaporative cooler is activated only when it is needed.
It has been the usual practice in the past to leave one or more windows open so as to allow the air from the evaporative cooler to escape. Thermostatic control of evaporative coolers under such conditions is not practical, because as soon as the cooler is turned off, hot outside air rapidly enters the house through the open windows. This produces rapid cycling of the cooler thereby defeating the purpose of the thermostat.
The thermostatic control system of the present invention is intended to be used in conjunction with an air shutter installed in the ceiling of the room which opens automatically when the cooler is operating due to the increased air pressure from the blower of the cooler, and which closes when the cooler is turned off. The windows may now be closed, and air is vented through the shutter into the attic and out the attic vent.